Patent GB-190709929-A (GB)
Title: Improvements connected with the Sighting and Aiming of Ordnance.
Inventor: PETCH ALBANY FRANCIS
Filed: 1907-04-29
Granted: 1908-03-19
Abstract: 9929. Petch, A. F., and Duncan, F. April 29. Sights and methods of sighting; mountings.-Relates to apparatus for sighting and elevating a gun automatically from a distant station. The cradle A, Fig. 1, carries an electric motor B operated by a distant range transmitter or directly from the range-finder and provided with a pinion b<1> gearing with a rack on a drum b<2>, which encircles the cradle. An arm b<3> on the drum b<2> carries a rubbing contact b' and strikers b<5>, b<6> to make contact with bars P, Q, R on a second drum C, which also encircles the cradle. Two other bars S, T are carried by the drum C, and the bar R is permanently connected to the bar S, and the bar Q to the bar T, the bars thus forming a simple two-way switch with an ' off ' position. The connecting wires are attached to a bracket b<7> carrying three brushes one of which is the negative main while the other two are switch wires which respectively connect to two solenoids in a relay E ; the other ends of the solenoids are connected to the positive main. The relay E actuates a reversing and starting rheostat F controlling an electric motor G which is preferably fitted with a magnetic brake g<7>. The drum C has range graduations c<1> to read with a pointer a, and the part c' is provided with a rack gearing with a wheel c<3> which rotates at the same speed as a wheel c<4>. A wheel c<5>, fast with the wheel c', engages a rack d' on the radius bar D which is pivoted to the pedestal at h<1>. Any movement of the cradle A will thus rotate the drum C through the gearing d<1>, c<5>, c<4>, c<3>, c<2>. The shaft of the motor G has a worm g<1> driving a worm-wheel g<2> fast with a pinion g<3> engaging a rack a' forming part of the cradle A. The arm H which carries the motor G is pivoted at h' to the pedestal, and carries a hand-wheel J actuating a worm j<1>, which drives a worm-wheel j<2> fast with a pinion j<3> engaging a rack k<1>, which forms part of a plate K fixed to the pedestal. By means of the hand-wheel J, the cradle A, radius-bar D, and arm H can be elevated together ; if the motor G is operated, the cradle A alone is moved. The construction of the strikers b<5>, b<6> is shown separately in Fig. 3, and the electrical connexions are shown in Fig. 5. The arm b<3>, Figs. 1 and 3. carries a metal casing m<1> within which are pivoted two arms b<5>, b<6> acted upon by springs tending to retain the arms against stops m<6>, m<7>. Each arm has a projection n<3>, n<4> and an adjustable platinum-tipped contact screw n<1>, n<3>, When the arm b<3> is in the central position, both arms are against the stops. Move. ment in either direction, say to the right in Fig. 3, causes the point n<2> to ride up the part r<1> of the bar R until. the projection n<4> engages the part r<2>, the point n<2> then breaking contact. In operation, the motor B is caused to rotate a definite amount from the range finder, the arm b<3> is thus rotated to a certain position, causing the motor G to elevate the cradle A. The elevation of the cradle imparts rotation to the drum C through the gearing c<4>, c<3>, &c., and this rotation continues until the contacts b<5> or b<6> are again disengaged from the bars Q or R. The hand-wheel J is operated to bring the sight on the target without altering the angle between the line of sight and the axis of the gun. The sight can be operated by hand from the hand-wheel c' by withdrawing the bolt d<2>. The radius-bar may be operated by the motor B, when the bolt d<2> is withdrawn, by connecting the drums b<2>, C by means of a pin b<8> in the arm b<3>. The wheels c<3>, c<4> may be connected by means of a supplementary disk c<9> and a variable-velocity device of the type described in Specification No. 13,814, A.D. 1907, so that the relative movements of the drum C and bar D may be varied to compensate for changes in muzzle velocity, temperature of the charge, &c.